Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Irish
toirneach
←
Proto-Celtic
*toranos
(derived)
←
Middle Irish
toirnech
(inherited)
←
Old Irish
torann
(derived)
→
Welsh
taran
(cognate)